In this proposal, we aim to use a systems biology approach to survey immune responsiveness across a range of different vaccines including influenza, both seasonal and the new pandemic H1N1v, Herpes zoster, Measles, and the bacterium Neisseria meningitidis. In the case of influenza and Herpes zoster, we will also be able to directly compare the immune response to vaccines with those natural responses to the pathogen itself. These investigations will compare different age groups-children, young adults, and the elderly-to look for specific markers and assays of immune competence and especially those that might be common across different pathogens and age groups. We will also survey the influenza vaccine responses of individuals with impaired or dysregulated immune systems in order to see how these might deviate from healthy individuals. We will employ a streamlined model in which clinical specimens from individuals exposed to different vaccines or infectious diseases will all be assayed for an array of basic immune functions in our Human Immune Monitoring Center and also for several "state of the art" assays such as our recently developed high throughput HLA sequencing technique, which is able to generate complete HLA haplotypes from hundreds of people simultaneously. We will also perform selected Immunoglobulin and T Cell Receptor repertoire analysis and combinatorial peptide-MHC tetramer analysis to efficiently search for informative T cell epitopes. We will employ advanced bioinformatics analysis such as our new cell type specific SAM algorithms (csSAM), which use cell subset information to achieve much higher sensitivity from whole blood gene expression data as well as developing new bioinformatics tools to interrogate our rich and complex data base across all projects, pilots and cores. RELEVANCE: In summary, we wish to analyze a variety of different disease/vaccine models in order to define common and unique characteristics of responder and non-responder individuals to develop new informative tools and assays that should be illuminating both to specific questions regarding these study groups and will also be of benefit generally with respect to "metrics" of immunological health and dysfunction. PROJECT 1 Title: Plasmablast Trafficking and Antibody Response in Influenza Infection and Vaccination Project Leader: Greenberg, H PROJECT 1 DESCRIPTION (provided by applicant): Plasmablast trafficking and antibody response in influenza infection and vaccination. The 2009 influenza pandemic reiterates the urgency in developing improved influenza vaccines. This pandemic is caused by the influenza A/H1N1 variant strain (H1N1v), to which much of the human population has little pre-existing immunity. H1N1v vaccines have recently been approved for distribution in the fall. This very uncommon circumstance with the advent of a new pandemic influenza strain provides the opportunity to address several critical questions regarding the B cell immunity against influenza, a key determinant of protection against influenza infection. Traditional evaluation for B cell responses against influenza infection or vaccination has relied heavily on convalescent serum antibody assays, which may not represent the entire antibody response, especially mucosal antibody responses that are frequently of great importance for protecting against respiratory pathogens. Antibody responses are first mediated by activated B cells, or plasmablasts, which migrate through circulation to different target sites and become effector B cells, or plasma cells. Recently we have developed a comprehensive flow cytometric assay to define the patterns of multiple trafficking receptor expression on blood plasmablasts, including those with trafficking signals for the respiratory tree. We have also developed sensitive methods to collect and analyze the polyclonal antibodies secreted by the plasmablast population or its specific subsets. Taking advantage of these new assays, and the rare opportunity provided by the H1N1v pandemic, we will address the following specific aims to: 1. Analyze the trafficking receptor profiles imprinted on plasmablasts after natural infection with those induced by immunization with two different influenza vaccines;2. define the quantitative and qualitative differences in plasmablast-derived polyclonal antibody (PPAb) responses to acute infection vs. mucosal or systemic vaccination in different age groups;3. qualitatively and quantitatively compare the homotypic and heterosubtypic PPAb reactivity induced by wild type H1N1v infection vs. the PPAb reactivity induced by the two types of H1N1v influenza vaccine, as well as by seasonal influenza vaccines. Together these aims will define new immune indicators and provide new insights to the mechanisms of B cell response to influenza infection and vaccination.